Fix some build symbol configuration.

Remove -gdwarf-4 from GYP build. This is the default for GCC 4.8 which is now required, so this command-line argument is redundant.

Only set use_debug_fission in the GN build in debug mode. This matches GYP. Release mode symbols will be non-fission.

Implement linux_symbols target in GN. Convert dump_app_syms from sh to Python for better GN usability, and it's more readable for normal programmers on the team.

BUG=

Review URL: https://codereview.chromium.org/1179393004

Cr-Commit-Position: refs/heads/master@{#334510}

build/common.gypi

@@ -3693,7 +3693,6 @@
             'cflags': [
               '-O>(debug_optimize)',
               '-g',
-              '-gdwarf-4',
             ],
             'conditions' : [
               ['OS=="android" and target_arch!="mipsel" and target_arch!="mips64el"', {

build/config/compiler/BUILD.gn

@@ -51,8 +51,8 @@ declare_args() {
   # with some utilities such as icecc and ccache. Requires gold and
   # gcc >= 4.8 or clang.
   # http://gcc.gnu.org/wiki/DebugFission
-  use_debug_fission =
-      !is_win && use_gold && linux_use_bundled_binutils && !use_ccache
+  use_debug_fission = is_debug && !is_win && use_gold &&
+                      linux_use_bundled_binutils && !use_ccache
 
   if (is_win) {
     # Whether the VS xtree header has been patched to disable warning 4702. If

build/linux/dump_app_syms.py

@@ -0,0 +1,29 @@
+# Copyright 2015 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+# Helper script to run dump_syms on Chrome Linux executables and strip
+# them if needed.
+
+import os
+import subprocess
+import sys
+
+if len(sys.argv) != 5:
+  print "dump_app_syms.py <dump_syms_exe> <strip_binary>"
+  print "                 <binary_with_symbols> <symbols_output>"
+  sys.exit(1)
+
+dumpsyms = sys.argv[1]
+strip_binary = sys.argv[2]
+infile = sys.argv[3]
+outfile = sys.argv[4]
+
+# Dump only when the output file is out-of-date.
+if not os.path.isfile(outfile) or \
+   os.stat(outfile).st_mtime > os.stat(infile).st_mtime:
+  with open(outfile, 'w') as outfileobj:
+    subprocess.check_call([dumpsyms, '-r', infile], stdout=outfileobj)
+
+if strip_binary != '0':
+  subprocess.check_call(['strip', infile])

chrome/BUILD.gn

@@ -808,4 +808,40 @@ if (is_linux) {
       "-e s/@@CONFDIR@@/$confdir/",
     ]
   }
+
+  action("linux_symbols") {
+    script = "//build/linux/dump_app_syms"
+
+    dump_syms_label = "//breakpad:dump_syms($host_toolchain)"
+    dump_syms_binary =
+        get_label_info(dump_syms_label, "root_out_dir") + "/" + "dump_syms"
+
+    chrome_binary = "$root_out_dir/chrome"
+    if (current_cpu == "x86") {
+      # Use "ia32" instead of "x86" for GYP compat.
+      symbol_file = "$root_out_dir/chrome.breakpad.ia32"
+    } else {
+      symbol_file = "$root_out_dir/chrome.breakpad.$current_cpu"
+    }
+
+    inputs = [
+      chrome_binary,
+      dump_syms_binary,
+    ]
+    outputs = [
+      symbol_file,
+    ]
+
+    args = [
+      rebase_path(dump_syms_binary, root_build_dir),
+      "0",  # TODO(GYP) This is linux_strip_binary if it is needed.
+      rebase_path(chrome_binary, root_build_dir),
+      rebase_path(symbol_file, root_build_dir),
+    ]
+
+    deps = [
+      ":chrome",
+      dump_syms_label,
+    ]
+  }
 }

chrome/chrome.gyp

@@ -349,6 +349,7 @@
     ['OS=="linux"',
       { 'targets': [
         {
+          # GN version: //chrome:linux_symbols
           'target_name': 'linux_symbols',
           'type': 'none',
           'conditions': [
@@ -357,14 +358,15 @@
                 {
                   'action_name': 'dump_symbols',
                   'inputs': [
-                    '<(DEPTH)/build/linux/dump_app_syms',
+                    '<(DEPTH)/build/linux/dump_app_syms.py',
                     '<(PRODUCT_DIR)/dump_syms',
                     '<(PRODUCT_DIR)/chrome',
                   ],
                   'outputs': [
                     '<(PRODUCT_DIR)/chrome.breakpad.<(target_arch)',
                   ],
-                  'action': ['<(DEPTH)/build/linux/dump_app_syms',
+                  'action': ['python',
+                             '<(DEPTH)/build/linux/dump_app_syms.py',
                              '<(PRODUCT_DIR)/dump_syms',
                              '<(linux_strip_binary)',
                              '<(PRODUCT_DIR)/chrome',